Intellectual Merit: This project will focus on how chemical signals mediate patterns of olfactory predation. We will correlate prey characteristics and environmental effects to the strength of the interaction between populations of particular predator and prey species. This project has 3 major experimental goals: (1). Quantify the structure of chemical plumes as functions of three variables: prey size, prey density, and turbulence. (2). Quantify how predators using different sensory mechanisms respond to variations in prey size and density, and turbulence. (3). Investigate how ambient turbulence, prey size, prey aggregation, and the interaction among these three parameters increases susceptibility to predation in the field. The synergistic result of the fluid mechanics, behavior, and field experiments will produce quantifiable linkages between prey and environmental characteristics and patterns of predation and community structures. The model system chosen for this study is the interactions between blue crab and gastropod predators and their infaunal bivalve prey. The behavioral disparities between rapidly (e.g. crabs) vs. slowly (e.g. gastropod) moving predators suggest they rely on different signal properties, and therefore may form a guild defined at least partially by the olfactory navigational strategies. As observed in the recent NSF workshop on future challenges in oceanography (OEUVRE), "fundamental advances in knowledge of turbulent mixing of the ocean at all scales will result in understanding a host of problems from water mass conservation to predator-prey interactions". This project will address how the fluid physics of chemical signal transport and the biological mechanisms of sensory reception mediate predation intensity in natural populations. Broader Impacts: This study focuses on important estuarine species (blue crabs, whelks, hard clams), each of which supports important fisheries in Georgia and elsewhere. Defining predation intensity as functions of physical and biological characteristics may be helpful for management of crab, whelk and hard clam populations. Training will be provided for two graduate (Ph.D.) students (one in Sensory Biology and one in Fluid Mechanics), and one Post-doctoral associate. These individuals will experience a rich interdisciplinary research environment in addition to developing the skills to be leaders in their respective fields. Undergraduate students will also be involved in data collection and analysis, particularly analysis of the behavioral tracks, PLIF, and field experiments. The undergraduate will gain valuable research experience and also will be exposed to interdisciplinary issues and perspectives. The School of Biology currently has a summer REU in aquatic chemical signaling and we expect that other undergraduates will develop projects that are related to this project, and which will capitalize on our integrative approach and techniques. This study will also connect well with on-going graduate educational efforts, in particular our NSF IGERT program to educate in the area of aquatic chemical signaling. Graduate students are typically supported during their first year in the program and are expected to be involved in research projects. Thus, in addition to the students supported by this proposal, perhaps two additional graduate students can be expected to be involved in the project each year. Laboratory exercises based on the methods and results of the proposed study will be developed for the IGERT courses. These exercises also will be used, possibly in a reduced form, for basic undergraduate laboratories in Ecology and Fluid Mechanics. This will give undergraduates exposure to interdisciplinary work, and foster an early appreciation for breaking down boundaries between disciplines.
